Gunnery control device for turret-mounted firearm

ABSTRACT

Device to give accurate information as to angular velocity of the turret and automatic interpolation of the tachometric and ballistic corrections dependent on speed, target distance and ballistic parameters in both the laying and sighting of the weapon so that the line of sight is held on target without any personal manipulation by the gun controller. A turret is driven through a reduction gear box by a hydraulic engine controlled by a servo valve. There is connected to the turret through the reduction gearbox a device including a stator and a rotor, the relative shift between the stator which is connected to the turret and the rotor being used to control in part the servo valve controlling the hydraulic engine driving the turret. The aforesaid rotor is connected to a cylinder driven by a rotating disk at a controllable variable speed inasmuch as the roller is coupled to the disk by displaceable balls which are displaceable diametrally along the disk. The position of the balls between the roller and the disk is controlled through a servo motor in turn controlled by a potentiometer responding to the laying device for the associated gun. A potentiometer indicates the position of the balls between the disk and roller and this information is fed to a potentiometer which is also provided with a signal representing the time required for a projectile to travel to a specific target. The resulting signal is fed to a reticle control in the associated sighting device and a signal is generated indicating the correction of the reticle for purposes of further controlling the aforesaid servo valve.

Unite States Maximi et al.

151 3,677,134 51 July 18, 1972 [s41 GUNNERY CONTROL DEVICE FORTURRET-MOUNTED [72] Inventors: Jacques Paul Robert Maxim], Tarbes; AndreBernard Maurei, Aureilhan, both of [21] Appl.No.: 23,845

[30] Foreign Application Priority Data March 31, 1969 France ..6909569[52] US. Cl. ..89/4l E, 89/41 H [51] Int. Cl. 413 3/22 [58] Field ofSearch ..33/49 B; 89/41 E, 41 EA, 41AA,

Primary ExaminerStephen C. Bentley I Attorney-Waters, Roditi, Schwartz &Nissen 57] ABSTRACT Device to give accurate information as to angularvelocity of the turret and automatic interpolation of the tachometricand ballistic corrections dependent on speed, target distance andballistic parameters in both the laying and sighting of the weapon sothat the line of sight is held on target without any personalmanipulation by the gun controller.

A turret is driven through a reduction gear box by a hydraulic enginecontrolled by a servo valve. There is connected to the turret throughthe reduction gearbox a device including a stator and a rotor, therelative shift between the stator which is connected to the turret andthe rotor being used to control in part the servo valve controlling thehydraulic engine driving the turret. The aforesaid rotor is connected toa cylinder driven by a rotating disk at a controllable variable speedinasmuch as the roller is coupled to the disk by displaceable ballswhich are displaceable diametrally along the disk. The position of theballs between the roller and the disk is controlled through a servomotor in turn controlled by a potentiometer responding to the layingdevice for the associated gun. A potentiometer indicates the position ofthe balls between the disk and roller and this information is fed to apotentiometer which is also provided with a signal represent ing thetime required for a projectile to travel to a specific target. Theresulting signal is fed to a reticle control in the associated sightingdevice and a signal is generated indicating the correction of thereticle for purposes of further controlling the aforesaid servo valve.

6 Claims, 2 Drawing Figures PATENTED JUU 8 m2 SHEET 1 [IF 2 MES kwmPATENTEB Juu8 I972 3,677,134

sum 2 OF 2 GUNNERY CONTROL DEVICE FOR TURRET-MOUNTED FIREARM FIELD OFTHE INVENTION This invention relates to systems for insertingcorrections into gun control devices.

BACKGROUND To insure a high probability of hitting a moving target onthe first shot requires the insertion of corrections which are dependenton the kinematic characteristics of the target, namely: its distance andrate of displacement with respect to the gun. In fact, to register a hiton a target maneuvering at distance D, at a velocity V perpendicular tothe line of sight, requires firing ahead of such target at an angulardisplacement equal to the product VT/D where T is the time of flight ofthe projectile corresponding to distance D, and V/D=Q is the apparentangular velocity seen from the turret.

SUMMARY OF THE INVENTION The device provided in accordance with thepresent invention permits the measurement of Q by means of a suitableaiming system and then, given the value of T, two equal and oppositeorders of firing correction can be elaborated and each of thesecorrections introduced respectively into the gun aiming and layingsystems so that the line of sight, after correction, stays aligned onthe target. The only constraint on the gunlayer is that prior to theautomatic insertion of those corrections, he must keep his line of sighton the target.

The improvements of the invention with respect to existing devices areof two kinds:

the measurement of velocity is far more accurate and less a matter ofchance thus insuring a better value of the correction instructions,particularly at long distances;

the automatic insertion of firing corrections into the weapon-layingsystem without intervention by the fire commander, that is to say,without change in his laying orders.

BRIEF DESCRIPTION OF DRAWING FIG. I is a schematic diagram of acorrection system provided in accordance with the invention; and

FIG. 2 is a view of a portion of the apparatus of FIG. 1 partiallybroken away.

DETAILED DESCRIPTION In the drawing, manual laying drives 1 aremechanically linkedto the slide of a potentiometer 2. The voltageobtained between the slide of that potentiometer and ground,proportional to the forced elevation, constitutes the order of referenceof a positional damping arrangement 3 of the governor shaft of avariable speed gear 4. This shaft in its movement operates the slide ofpotentiometer 5 known as the shaft position retrace. The voltagedelivered by this potentiometer is compared with the frame of referencein a differential amplifier 6 driving the servomotor 7.

The variable speed ball gear comprises three parts:

a disk 8 driven at constant speed by a synchronous motor 9;

a roller 10 driving the variable speed output shaft 10' and lying in aplane parallel with that of the disk;

a disk-to-roller connection through balls mounted in a flynut 11. Theballs move along the disk following a diameter parallel to a generatingline of the roller. The roller speed is proportional to the position ofthe balls on the disk. This is equal to zero when the balls are at thecenter of the disk and maximum when they are at the periphery. This wayand because of the properties of the ball speed change mechanism 4, anextremely uniform delivery speed is obtained and indicated accurately bypotentiometer 5 which duplicates the position of the balls.

The delivery shaft 10' of roller 10 of the speed change drives, atforced" speed (I, the rotor of an angular position interceptor 12, whosestator is mechanically connected to the turret by the reduction gearbox13. An angular shift between the interceptor rotor and stator producesan electric signal proportional to such shift which constitutes thedamping error signal for the position of the turret at the sightingorder Amplifier l4 amplifies the control error signal and governs thehydraulic output of a servo valve 15. Thisservo valve feeds thehydraulic engine 16 which drives turret 17 by means of reduction gear 13in the direction tending to cancel out the angular displacement.

The measurement of target speed derives directly from the sightingdevice. In order to learn the target speed of progress, the gunlayerchases it. To this order of sighting, there is only one correspondingposition of the balls on the disk, of which position the electricalvalue is known through potentiometer 5. This electrical equivalent isalso that of the rate of progress. The basis of the detennination of thetachometric correction is as follows:

The gunlayer chasing the target with his range finder integrally mountedon the gun, has the turret rotating at speed (I. The electronicmultiplier works out the product of Q by T where Q is an electricvoltage feeding a potentiometer 18, in which the position of the contactslide is a function of T. The result of the product is an electricvoltage representing the value a Q T of the firing correction angle.This value is brought into the aiming system where it constitutes thedamping entry order 19 for the vertical cross hair 20 which then movesby an. amount equivalent to a. This reticle displacement is joined tothat of the slide of potentiometer 21 which works out the correctionorder which is added to the aiming command in amplifier 14 of servovalve 15 so that the instantaneous movement of the turret ahead of thetarget is equal to angle a.

For the gunlayer, at the end of correction, the target is displaced inthe field of his sight gage, but the aiming marks being correctlyoffset, the line of sight remains fixed on the same point of the targetas before the correction. This automatic insertion on the gunlayer orderand the matching of the turret and reticle displacements requires nochange in the aiming orders, since after the correction, the gunlayercontinues to chase the target and can fire in the best time-limit forsuch intervention.

In the above, there is disclosed a system for the automatic insertion offiring corrections for gun control devices. The system comprises asighting means whose bearing is mechanically secured to remain parallelwith the firing axis. The arrangement consists of a means capable ofshifting the axis of sight or the sight line marks or reticle inproportion to the corrections and associated with a positional shift ofthe line of fire, of which the initial command is made up of the sum ofthe laying or bearing entries and an amount whose value is equal andopposite to the value of the corrections so that when those correctionshave been inserted, the firing line moves by an amount equal andopposite to the line of sight which thus stays fixed on target.

In the said system, the correction inserted is the firing correction ona moving target. The said firing correction on moving target depends onthe following:

a. first, a method capable of generating a quantity of which at anyinstant the value (I) and the value of the derivative 0 are known, thequantity 4: constituting the aiming order;

b. a second method to generate an amount proportional to the product ofthe derivative 9. by an amount proportional to the time of flight T ofthe projectile and to shift the axis of sight or the sight line marks byan angle a equal to the quantity represented by that product so that theline of sight shifts inversely to the direction of the target;

c. a third method to hold down the position of the line of fire to arequired position, whose initial command is made up of the sum of theaiming orders and correction orders.

The quantity .0 mentioned above is in proportion to the speed of thedelivery shaft of an electromechanical pilot system and variable speedgenerator, the aiming order being proportional to the angular positionof the said delivery shaft. The quantity is an electric voltage, thequantity 4: being ascertained after that voltage has traveled into anintegrating amplifier. The delivery shaft of said electromechanicalpilot variable speed generating system is that of a variable reducerhaving a ratio K associated with a control of its adjustmentdriveposition.

The said adjustment-drive position control comprises: a motor-generatordriving the variable reducer feedshaft at speed K; an amplifiercontrolling the voltage of the motor windings, starting from the voltagedifference between the reference voltage proportional to KS) and thevoltage of the tachogenerator associated with the motor.

The electromechanical pilot variable speed generating system mentionedabove has an output shaft which is that of a mechanical variable speedreducing gear whose primary shaft is driven at constant speed and ofwhich the mechanical adjustment of the reduction ratio is effected bypositional control of the adjustment drive.

The aforesaid means of controlling the position of the axis of firecomprises: an angular drift detector made up of a stator connected tothe turret by gearing and a rotor integral with the output shaft of theelectromechanical pilot variable speed generating system; an integratingamplifier receiving the electrical signal resulting from the shiftbetween the detector stator and rotor for a set aiming angle and theelectrical signal corresponding to the firing correction angle; and amotor driving the turret by means of a reducing gear in a directionleading to cancellation of the control signals.

The integrating amplifier mentioned above as relating to control of thefiring line or axis, comprises: an angular position detector whosestator is stationary and whose rotor is connected to the turret bygearing, delivering a voltage equal to the electrical value of theeffective aiming angle (p, of the turret; a differential amplifier tocompare the electrical value of the required aiming angle 11; to thevalue of the effective aiming angle and a motor driven by the errorsignal resulting from a comparison between 4; and (1: and driving theturret through a reducing gear in a direction leading to cancellation ofthe error signal.

The angular drift detector is made up of a synchro transmittergenerating the required aiming value 4), with a rotor integral with theoutput shaft of the aforesaid electromechanical pilot variable speedgenerating system; a differential synchro which allows addition to thevalue 41 of the value of the angle a for firing correction introduced bythe shift of said angle a of the rotor in respect to the stator; and asynchro receiver whose stator is stationary and whose rotor which isconnected to the turret by gearing generates a voltage of amplitudeequal to the electrical value of the angular difference between theposition of the turret and the required position after correction.

The angular drift detector, in which the synchro transmitter is aresistance or induction potentiometer, whose stator is integral with theturret and whose rotor is driven by the shaft of the electromechanicalpilot variable speed generator system, delivers a voltage equal to theelectrical value of the angular difference between the turret positionand the position of the output shaft of the said electromechanical pilotsystem.

The motor mentioned above is a hydraulic motor driving the turret, itsoutput being controlled by one or more servo valves electrically drivenon the basis of the sum of aiming orders and fire correction orders.

The quantity 9 mentioned above is a frequency, the quantity dz being anumber N of pulses, each pulse representing an increment in aimingangle. The subjecting of the firing axis to the aiming and correctioninstructions is effected by the aid of a picking motor. At each pulse,the motor shifts the gun axis by one angle increment. A numericaltotalizer sends the picking motor the sum of the N pulses correspondingto the aiming instruction and of those corresponding to the correctioninstruction.

A second picking motor receiving only the pulses equivalent to thecorrection instruction shifts the sightline marks by an amount equal andopposite to the angular displacement of the firing axis ahead of thetarget.

The working-out of the correction mentioned above is obtained in thesaid second method by a multiplier made up of a potentiometer fed by anelectric voltage proportional to speed .0. of the turret and theposition of whose slide is controlled at value T of the projectile timeof flight. The voltage indicated on the slide is proportional to thevalue of the angle a 07 and constitutes the correction instruction forshifting of the line of sight and backing-in of the axis of fire aheadof the target.

The working-out of the correction mentioned above is obtainedexclusively by electrical multiplication of the values 0 and T given inthe form of analog or numerical electrical magnitudes.

A shot at a moving target can be carried out in two phases:

First phase: The marksman follows the designated target by action on thehandles 1. Since the viewing device is gimballed to the gun, the pursuitof the target consists of permanently aligning the vertical hairline ornetwork on that target. During this phase, the vertical hairline remainsin the center of the optical field of the viewing device, the telemetryis operative and there are provided the two perimeters O and T f (D) forderiving instantly and continuously the product a (IT.

Second phase: The marksman introduces the correction at by closing theswitch 22. At this moment, he perceives in the viewing device thesimultaneous displacement of the target and the vertical hairline in thesame direction. The target is displaced due to shifting of the gun andthe viewing device by a quantity or leading the target and the hairlineis displaced by a same quantity in the opposite direction to the target.At the end of correction, the vertical nairline is still on target butthe gun is pointing to the future target position. In accordance withthis principle, the correction or shift of the gun occurs without anyneed for modifying the position of the handles 1.

What is claimed is:

1. Apparatus comprising a gun having a firing axis, a rotatable turret,means for supporting the gun, laying means for controlling the gun,sighting means associated with the gun to move therewith, said sightingmeans having a line of sight, correction means to determine positioncorrections for the gun and to displace the gun in accordance with saidcorrections to shift said firing axis and line of sight so that the lineof sight can remain fixed on a target when directed at the target by anoperator, said turret means including a turret, a source of power forrotating the turret, a reduction gear means coupling said source to saidturret, and an angular position interceptor including a rotor andstator, the stator being coupled by said gear means to said turretwhereby the relationship of the rotor relative to the stator indicatesthe position of the turret.

2. Apparatus as claimed in claim 1 comprising a variable speed gear torotate said rotor and control means to control said variable speed meansin response to said laying means.

3. Apparatus as claimed in claim 2 wherein said variable speed gearincludes a disk, a motor rotating said disk, a roller parallel to saiddisk and rotatable means between the roller and disk and adjustablediametrally along the latter and longitudinally along the roller, saidroller being coupled to said rotor.

4. Apparatus as claimed in claim 3 wherein said control means is coupledto and adjusts the position of said rotatable means, said correctionmeans including a potentiometer coupled to said laying means and a servomotor coupled to said potentiometer and operating said control means.

5. Apparatus as claimed in claim 4 comprising a second potentiometerindicating the position of said rotatable means, a third potentiometercoupled to said potentiometer to receive a signal therefrom representingS). wherein n. is the angular velocity of a target perpendicular to theline of sight, and being further adapted to receive a signalrepresenting T wherein T is the time of flight of a projectile to saidtarget, said axis and line of sight, said source of power including acontrol valve and an operating means coupled to and operating saidcontrol valve and in turn coupled to and operated by said rotor andfourth potentiometer.

UNITEDSTATES PATENT UFHQE (1E TEHCATE 0F Q6 EQ'HQN Patent No. 3,677,134Dated July 1.8, 1972 Inventor(s) Jacques Paul Robert Maxims et a1 It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

0n the cover sheet [72] the inventor's name "Jacques Paul Robert Maximi"should appear Jacques Paul Robert Maxime Signed and sealed this 12th dayof December 1972'.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. I ROBERT GOTTSCHALK Attescing Officer Commissionerof Patents FORM PO-1050 (10-69) *1 us. GOVERNMENT PRINTING OFFICE: 1969o-36s-3:14,

UNITEDSTATES PATENT OFFICE CERTIFICATE OF CORRECTION I Patent No.3,677,134 Dated 'July 18, 1972 Inventor(s) Jacques Paul Robert Maxime et31 It is certified that error appearsin the above-identifiedpatent andthat said Letters Patent are hereby corrected as shown below: 7

-.On the cover sheet [72] the inventor: name "Jacques Paul RobertMaximi" should appear Jacques" Paul Robert Maximo d Signed and sealedthis 12th day of December 1972'.

(S Attest:

EDWARD M.FLETCHER,JR. I ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents USCOMM-DC 6087 6-P6Q FORM PO-1050 (10-69) v: u.s. GOVERNMENTPRINTING OFFICE: 1969 o-ase-au.

1. Apparatus comprising a gun having a firing axis, a rotatable turret,means for supporting the gun, laying means for controlling the gun,sighting means associated with the gun to move therewith, said sightingmeans having a line of sight, correction means to determine positioncorrections for the gun and to displace the gun in accordance with saidcorrections to shift said firing axis and line of sight so that the lineof sight can remain fixed on a target when directed at the target by anoperator, said turret means including a turret, a source of power forrotating the turret, a reduction gear means coupling said source to saidturret, and an angular position interceptor including a rotor andstator, the stator being coupled by said gear means to said turretwhereby the relationship of the rotor relative to the stator indicatesthe position of the turret.
 2. Apparatus as claimed in claim 1comprising a variable speed gear to rotate said rotor and control meansto control said variable speed means in response to said laying means.3. Apparatus as claimed in claim 2 wherein said variable speed gearincludes a disk, a motor rotating said disk, a roller parallel to saiddisk and rotatable means between the roller and disk and adjustablediametrally along the latter and longitudinally along the roller, saidroller being coupled to said rotor.
 4. Apparatus as claimed in claim 3wherein said control means is coupled to and adjusts the position ofsaid rotatable means, said correction means including a potentiometercoupled to said laying means and a servo motor coupled to saidpotentiometer and operating said control means.
 5. Apparatus as claimedin claim 4 comprising a second potentiometer indicating the position ofsaid rotatable means, a third potentiometer coupled to saidpotentiometer to receive a signal therefrom representing Omega whereinOmega is the angular velocity of a target perpendicular to the line ofsight, and being further adapted to receive a signal representing Twherein T is the time of flight of a projectile to said target, saidthird potentiometer being coupled to and controlling said adjustmentmeans.
 6. Apparatus as claimed in claim 5 wherein said adjustment meansincludes a fourth potentiometer coupled to said third potentiometer andindicating the relative shifting of the firing axis and line of sight,said source of power including a control valve and an operating meanscoupled to and operating said control valve and in turn coupled to andoperated by said rotor and fourth potentiometer.